Method
1) Bring the cream to a gentle boil in a pot. Make sure the bottom is not burnt.
2) Dice the chocolate into small pieces and place it in a bowl.
3) Pour the boiling cream into the chocolate.
4) Use a wooden spoon to stir the cream + chocolate mixture till chocolate melts completely.
5) Stir in butter till melted and ganache is smooth.
6) Leave to set overnight in room temperature (Below 26C at least) before use.